Conventionally, the operation of a brake of a hoisting machine of an elevator is measured with a limit switch, which is fixed to the side of the brake. The limit switch is configured to measure the movement of the armature part with respect to the frame part of the brake. The limit switch comprises a moving arm, which is attached to a contact of the limit switch in such a way that the contact opens and closes as the arm moves.
The limit switch is attached to the frame part of the brake and the arm is fixed to the armature part moving in relation to the frame part.
The movement of the armature part is seldom straight with respect to the frame part, and typically the armature part strikes obliquely against the frame part of the brake. In this case the movement can also be smaller on one side of the brake than on the other side. If the limit switch is on the side with small movement, observation of the movement is difficult.